Not Applicable.
In the assembly of race cars with rear wheel drive with a differential gear in the rear and engine and transmission in the front of the race car, it is necessary to align the axis of the output shaft of the transmission with the input shaft of the differential gear to avoid vibration and to improve performance. Current practice for aligning the axis of the transmission output shaft with the input shaft of the differential gear has been by trial and error and through observations. A need exists for an improved alignment system to facilitate proper positioning of the differential input shaft relative to the transmission when a race car is being assembled.
An apparatus for use in assembling the drive train of a race car is disclosed.
The present invention provides apparatus for use in aligning the differential input shaft of a race car with the transmission output shaft of the race car. With the drive shaft removed from the drive train, a transmission attachment is detachably mountable to the transmission of the race car in place of the drive shaft. The transmission attachment includes a plate mounted to a shaft which extends axially from the plate. The shaft may be coupled with the output shaft of the transmission by its being received on the output shaft of the transmission. A first laser is mounted in a central opening in the plate such that the laser will emit a light beam aligned with the axis of the output shaft of the transmission. The plate includes concentric markings on its face which are centered on the central opening.
A second part of the apparatus is a differential input shaft attachment which may be mounted to the differential input shaft assembly while the drive shaft of the race car is removed from its coupling to the differential gear. The differential input shaft attachment may be mounted to the differential yoke which is coaxially mounted to the input pinion shaft of the differential gear. The differential input shaft attachment includes a plate which is mountable to the differential yoke such that the plate is perpendicular to the axis of the input pinion shaft of the differential. The plate of the differential input shaft attachment has a second laser mounted within a central opening in the plate. The second laser will emit a light beam aligned with the axis of the input pinion shaft of the differential input shaft and directed toward the transmission. The second plate also includes concentric markings on its face which are central on the central opening.
When the lasers are activated, adjustment of the orientation of the differential input shaft centerline relative to the transmission can be carried out by moving the differential gear or the rear of the transmission to a position where the beams from the first and second lasers are not intersecting. The concentric markings on the plates allow the user to easily assess the distance from the center of the plate at which the opposing laser beam is striking the plate. By introducing a fine dust from a powder such as corn starch or the like into the region between the plates, the laser beams can be observed and adjustment of the differential input shaft can be accomplished to the point where the laser beams do not intersect. With the input shaft of the differential input shaft aligned with or parallel with the output shaft of the transmission of the race car, optimum performance of the drive train is obtained. The first laser may be identical and interchangeable with the second laser and each may emit a red beam. However, lasers which emit differing beam colors may be employed in order to differentiate the laser of the transmission attachment from the laser of the differential input shaft attachment.
The apparatus may also be used to analyze alignment of the differential input shaft to the transmission through the range of vertical motion of the differential input shaft permitted by the race car""s suspension. This may be done while the race car remains stationary by mechanically lifting the differential input shaft relative to the race car""s chassis while the transmission attachment and the differential input shaft attachment remain temporarily attached to the transmission and the differential input shaft respectively. In this manner, the alignment of the differential input shaft to the transmission output shaft can be inspected throughout the range of vertical motion of the differential input shaft.
In a variation of the invention, either laser may be removed from the central opening of the plate in which it is installed and a target element may be placed in the central opening in its place. The target element has a center indentation or other centered target mark for use when the user desires to reposition the transmission or differential input shaft such that the laser mounted to the one of the gear assemblies is aligned exactly with the axis of the other gear assembly.
In another variation, the laser of either attachment may be removed and replaced with an adapter which allows measurement of the pinion angle of the differential input shaft or the transmission of the race car by mounting a standard camber gauge in axial alignment with the differential input shaft or the transmission output shaft depending on which gear assembly is to be tested. The camber gauge which may be used for this measurement is a typical gauge used to mount to the spindle of a vehicle wheel to measure the camber (tilt from vertical) of the wheel and includes a first transverse level which can be used to place the camber gauge in a horizontal orientation relative to its short axis. A pair of longitudinal elongate bubble levels are positioned parallel to the long axis of the camber gauge and will indicate the decline or incline from horizontal, in degrees, of the shaft of the gear assembly whose attitude is being measured. With the use of this variant of the invention, the pinion angle of the differential input shaft or of the transmission can be compared with the angle present when the differential input shaft and transmission have been accurately aligned by use of the primary system using opposing lasers as described above.
It is a primary object of this invention to provide apparatus for use in accurately aligning the differential input shaft with the transmission of a race car during the assembly of the race car drive train.
It is also an object of the invention:
to provide an easily mounted and used apparatus for detection of non-parallel alignment of the output shaft of the transmission with the input shaft of the differential gear of a race car;
to provide an adaptable apparatus which permits visual detection at the differential of a race car of an emitted laser beam of a laser aligned with the axis of the output shaft of the transmission of the race car, or to allow visual detection at the transmission of an emitted laser beam of a laser aligned with the input shaft of the differential of the race car; and
to provide an adaptable apparatus which permits axial attachment of a camber gauge to the output shaft of a transmission of a race car to measure the pinion angle of the output shaft of the transmission;
to provide an adaptable apparatus which permits axial attachment of a camber gauge to the input shaft of a differential gear of a race car to measure the pinion angle of the input shaft of the differential gear.
These and other objects of the invention will become apparent from examination of the description and claims which follow.